Braking band of a disc for disc brake of ventilated type

ABSTRACT

A braking band of a disc brake disc has two mutually facing plates having inner surfaces, directly or indirectly facing and delimiting a gap, outer surfaces having flat and opposite circumferential portions which form braking surfaces, and plate bodies having predetermined plate thickness. The plates are joined to each other by connecting elements shaped as columns or ribs which project from one plate towards an opposite plate in the form of bridges which connect the plates. At least one of the plates has at least one shaped pin projecting from a plate into the gap reaching the opposite plate, forming at least one localized narrowing of the gap and a thickening of the plate body, creating a localized increase of the predetermined plate thickness. At least one shaped pin extends from a first connecting element to an adjacent connecting element, connecting the connecting elements, and along a circumferential direction connecting at least two adjacent connecting elements.

FIELD OF THE INVENTION

The present invention relates to a braking band and to a ventilated discfor disc brake, particularly, but not exclusively, for applications inthe automobile field, as well as to a vehicle having said ventilateddisc.

Background Art

The brake caliper in a disc brake is generally arranged straddling theperipheral outer margin of a brake disc, adapted to rotate about arotation axis (A-A) defining an axial direction (X-X). A radialdirection (R-R) is also defined in a disc brake, which radial directionsubstantially is orthogonal to said axial direction (X-X), and acircumferential direction (C-C), which is orthogonal both to said axialdirection (X-X) and to said radial direction (R-R), as well as atangential direction (T-T) which is locally, or better punctuallyorthogonal, both to said axial direction (X-X) and to said radialdirection (R-R).

As known, the discs for disc brake comprise a bell adapted to associatethe disc with a hub of a vehicle, from which an annular portion extends,called braking band, intended to cooperate with brake pads of a caliper.In the case of discs of ventilated type, the braking band consists oftwo plates facing and connected to each other, respectively, by means ofconnecting elements, for example in the form of pins or fins. The outersurfaces of the two plates define opposite braking surfaces, while theinner surfaces delimit, jointly with the pins or the fins, ventilationchannels for cooling the disc, channels in which air flows according toa centrifugal direction during the rotating motion of the disc itself.

Said braking band is intended to cooperate with calipers for disc brakeadapted to exert a braking action on the vehicle, thus exerting, bymeans of the aforesaid pads, friction on the opposite surfaces of thetwo plates, said braking surfaces.

It is known that during the actuation of the brakes, the frictionbetween the pads of the brake calipers and the braking surfaces of thebraking band generates an increased quantity of heat which requiresbeing dissipated.

The heat generated indeed causes the occurrence of several undesiredphenomena, such as the deformation of the braking band, the formation ofcracks on the braking surfaces or localized transformations of state ofthe material forming the braking band which in turn result in thedeterioration of the braking band itself.

In particular, in the applications on high performance motor vehicleswith an increased braking efficiency, the energy to be dissipated isquite high and the aforesaid need to dispose of the heat generated bythe braking action is even more felt.

Ventilated discs of the aforementioned type have undergone a continuousevolution over time, in particular concerning the number and shape ofthe so-called ventilation channels, thus defining the gap formed by thetwo mutually axially facing plates.

Among the known ventilated discs, the so-called “pin” discs have shownto be particularly efficient in terms of heat dissipation, i.e. cooling,in which ventilation channels are internally limited by particularpillar connecting elements having limited or substantially littledeformed radial and circumferential extension with respect to the axialextension thereof, defined as “pins”, which transversely connect the twoplates.

For example, “pin” ventilated discs are known from EP 1 373 751 B1, inwhich the pins are geometrically arranged along three concentriccircumferences, which are coaxial to the disc and having differentradius, to form three “ranks”; if sectioned on a plane parallel to thetwo plates and which is median with respect thereto, the pins havesections of various type (for example, pins with “rhomboidal” sectionsin the intermediate and inner ranks; “drop-shaped” pins in the outerrank).

Other ventilated discs with “pin” structures are known, for example fromWO 2004/102028 and from U.S. Pat. No. 5,542,503.

The known ventilated discs include the so-called “fins” or “tabs” discs,in which the ventilation channels are internally limited by particularconnecting elements elongated along a main direction, for exampledirected according to a direction parallel to the radial direction(R-R), or spiral, and which transversely connect the two plates.

It likewise is known that the braking action performed by the padsagainst the braking surfaces of the disc generates heat, therefore anincrease in temperature of the disc up to making the disc itselfincandescent in the case of particularly onerous performance. Due to theincreased temperature reached by the disc during the braking, the discis deformed and the contact between the pads and the braking surfacesdeteriorates. Moreover, the friction material of the pads undergoes akind of vitrification and pollution by the material of the disc.

It has also been noted that the highest temperature is reached at anannular central portion of the braking surfaces, i.e. at an annularcentral portion of the outer surfaces of the respective plates. Duringthe life of the disc, such a zone is easily subject to the formation ofcracks.

To obviate the above-mentioned drawbacks, the need on the one hand istherefore particularly felt in the field to increase the efficiency ofthe dispersion of the heat generated by the braking so as to contain thetemperatures reached by the disc during and following the braking, andon the other hand, the need to increase the mechanical resistance ofthese central portions of the braking band.

Solutions are known from WO 2004/102028 and from WO 2002/064992, U.S.Pat. Nos. 7,066,306, 7,267,210, US 2006 0243546, US 2004 0124047, U.S.Pat. Nos. 6,367,599, 5,542,503 and 4,865,167, as well. Although they aresatisfactory from various viewpoints, these known solutions do not allowa compromise to be reached between the desired mechanical resistance inthe central annular zone of the braking band and the contrasting need tomaximize, in the same zone, the flow of air capable of removing thestrong localized increase in temperature caused by the braking action.

However, it is worth noting that ventilated discs of the mentioned typedo not provide per se a solution to a further problem which occurssimultaneously with the above-mentioned problems and which is to besolved at the same time, which problem may affect the disc brakes, inparticular the disc brakes with ventilated discs, the problem beingbriefly disclosed hereinbelow.

As known, during the bake actuation, the disc and the braking bands, inparticular, may mechanically vibrate at various frequencies correlatedwith the various vibration modes of the disc itself. Such vibrations ofthe disc may result, for example from resonances triggered by vibrationsof objects mechanically coupled to the disc which are stressed inbraking step should the vibration frequencies of such objects coincidewith or be sufficiently close to the vibration frequencies of the disc.

It is also known that the above vibrations cause audible noise, inparticular in the form of annoying whistling, when the resonancefrequencies are in the audible range (for example, between 2 and 9 kHz,with subsequent more or less acute whistling).

Therefore, the need emerges of devising solutions for reducing oreliminating such whistling by means of constructing contrivances which“move” the vibration frequencies of the disc to different values thanthe excited ones.

Some solutions are known for discs with different structures from thementioned “pin” structures.

For example, IT 1 273 754 has braking bands with protrusions projectinginto the inner part of the plates, towards the gap between the twoplates, in particular positions and with masses specifically identifiedin order to reduce the vibrations which occur and the subsequent noise.

Other ventilated discs with structures adapted to reduce annoyingvibrating phenomena are known, for example from U.S. Pat. No. 4,523,666.

U.S. Pat. No. 3,983,973 to Knorr-Bremse GmbH shows a brake disccomprising a pair of friction plates spaced apart from each other toform a ventilation channel. A braking force may be applied against saidplates by means of a brake pad braking gasket. The two plates areinterconnected by a plurality of ribs or flow guide fins so as to defineventilation passages between the friction plates. Strips ofanti-vibration material are positioned in radial grooves formed in themutually facing surfaces of the friction plates. These inserts areformed by metal elements which dampen the vibrations and have a greaterexpansion coefficient than that of the ferrous material of which thefriction plates are made, such as lead, bronze, or copper.

A similar solution is known from US2009035598.

It is known from document US2012111692 to couple passive dampers of theSquawk type with the braking device to reduce the vibrations.

It is known from solutions U.S. Pat. No. 6,131,707, WO2016020820,WO2017153902, WO2017153873, EP0318687, WO2011058594, WO2006105131,US2006219500, U.S. Pat. No. 6,145,636, US2010122880, U.S. Pat. Nos.6,325,185, 4,523,666, U.S. Pat. No. 5,004,078, SI23474, GB2060796,DE102013210700, EP3421833, WO2015092671, GB2286438, DE102004056645,EP2192321, WO2008078352, U.S. Pat. No. 3,983,973, DE202006017092,US20090000884, DE202015102580 to provide connections between theunevenly-distributed plates of the circumferentially-distributed brakingband in order to reduce the vibrations excited by the braking action andto increase the ventilation in the gap.

However, these distributions of the connecting elements of the platescreate structural non-uniformities capable of generating entirelyunwanted stresses concentrated in the braking band under certaincircumstances of the braking action.

Therefore, the need arises for new structures of ventilated discs whichare capable of simultaneously offering, in braking step, bothparticularly efficient cooling performance and vibration and noiseminimization properties, while avoiding concentrated stresses in thebraking band which could compromise the integrity and life thereof.

The aforesaid known examples of ventilated discs and related brakingbands are not capable of adequately meeting all the mentioned andstrongly desired needs.

Document EP 2 715 179 B1 to the same Applicant partially solves theseproblems, and in particular attempts to reduce the frequencies of thevibrating modes of the braking band which result in vibrations outsidethe plane itself of the plates of the band itself. In particular, thissolution has shaped pins which project into the gap, which are arrangedbetween connecting elements.

Although satisfactory from many viewpoints, this known solution does notcompletely solve the problem, and in particular has highlighted how theneed is felt to find solutions which allow the shape of the surfacesdelimiting the gap of the braking band to be obtained.

Therefore, the need remains strongly felt to increase the mass of thebraking band close to the outer edge thereof in order to reduce thevibrating modes of the braking band of the “out of plane” type whichaffect the performance of the brake quite negatively if excited.

Simultaneously, the need remains strongly felt to keep a distancebetween shaped pins and connecting elements, especially close to theouter edge of the disc, for example to simplify the production processof the core which allows making the braking band by founding: since thegeometry of the pins is achieved due to the core which geometricallyrepresents the spaces between one pin and the other, it is required toensure minimum sections so the sand for the cores is capable of fillingall the spaces which form the gap and furthermore, said core has minimumsections capable of providing a structural resistance of the core itselfwhich is sufficient for the handling thereof and the melting of thebraking band.

Furthermore, the contrasting need is strongly felt to avoid a broadannular area of the gap which is empty of connecting elements orprotrusions, thus avoiding a poor distribution of the temperature on thebraking band such as to generate a vibration of the disc or otherout-of-balance phenomenon.

Therefore, the problem at the basis of the present invention is that ofdevising a braking band and a disc for disc brake which have structuraland functional features such as to meet the aforesaid needs whileobviating the drawbacks mentioned with reference to the known art.

Solution

The present invention aims to provide a braking device in which thetendency to create these vibratory waves and subsequent whistling isreduced.

These and other objects and advantages are achieved by a braking bandaccording to claim 1, as well as by a disc brake disc according to claim9, as well as by a vehicle according to claim 10.

Certain advantageous embodiments are the subject of the dependentclaims.

From the analysis of this solution, it has emerged how the solutionsuggested allows a superior braking comfort to be achieved with respectto solutions of the prior art, therefore a reduction of the vibrations,and in particular an absence of vibrations resulting in whistling.

Moreover, the solution suggested maintains a very high, and in certainembodiments even improved, disc cooling efficiency, for example theefficiency is strongly improved due to the increased turbulence of theflow of air flowing through the gap of the braking band, a turbulencecaused by the specific shape of the shaped pins between and the platesand arranged between the connecting elements and extending incircumferential direction.

Furthermore, the solutions suggested allow the mass of the braking bandarranged close to the outer edge thereof to be increased in order toreduce the vibrating methods of the braking band of the “out of plane”type which affect the performance of the brake quite negatively ifexcited.

Still further, due to the solutions suggested, a distance may be ensuredbetween the shaped pins and the connecting elements, especially close tothe outer edge of the disc, thus simplifying the production process. Forexample, there was detected a minimum distance to be ensured between theconnecting elements and the shaped pins (variable from 5 mm to 7 mm,typically 6 mm) for the convenient feasibility of the founding core withwhich the braking band is made: since the geometry of the connectingelements is achieved due to the core which geometrically represents thespaces between one connecting element and the other, it is required toensure minimum sections in order for the foundry sand to be capable offilling all the spaces, as well as to ensure the structural resistanceof the core itself.

Still further, due to the solutions suggested, it is possible to avoid abroad annular area of the gap which is empty of connecting elements orshaped pins, thus avoiding a poor distribution of the temperature on thebraking band such as to generate a vibration of the disc or anotherout-of-balance phenomenon.

Still further, due to the solutions suggested, the mass close to theouter edge may be increased while avoiding an excessive occlusion ornarrowing of the ventilation channel, while structurally strengtheningthe band to limit the formation and propagation of cracks.

Still further, an increase in the resistance to braking due to anelevated temperature may be ensured due to the solutions suggested.

Still further, shaped pins capable of further increasing the availablesurface for the heat exchange may be ensured due to the solutionssuggested.

DRAWINGS

Further features and advantages of the device, disc brake and vehiclewill become apparent from the following description of preferred andnon-limiting embodiments thereof, with reference to the accompanyingdrawings, in which:

FIG. 1 shows an axonometric view of a braking band according to thepresent invention;

FIG. 2 shows a plan view of the braking band in FIG. 1, sectioned alonga median flow plane of the fluid which flows through the gap;

FIG. 3 shows an enlarged detail of the section of braking band in FIG.2;

FIG. 4 shows an axonometric view of a detail of the section in FIG. 3;

FIG. 5 shows a section of the braking band in FIG. 1, along a planecontaining the axial and radial direction, in which the shapes of thefurther shaped pin are noted;

FIG. 6 shows a section of the braking band in FIG. 1, along a planecontaining the axial and radial direction, in which the shapes of theshaped pin are noted;

FIG. 7 shows an axonometric and partially cross-sectioned view of thebraking band in FIG. 1;

FIG. 8 shows a section of a brake disc comprising a braking bandaccording to the present invention, along a plane containing the axialand radial direction.

DESCRIPTION OF SOME PREFERRED EMBODIMENTS

According to a general embodiment, a braking band 1 of a disc for discbrake 2 of ventilated type is provided.

Said braking band 1 extends between an inner diameter D1, close to arotation axis X-X of the braking band 1, and an outer diameter D2, farfrom said rotation axis X-X. Said rotation axis defines an axialdirection X-X.

Said braking band 1 defines a radial direction R-R, substantiallyorthogonal to said axial direction X-X, and a circumferential directionC-C, orthogonal both to said axial direction X-X and to said radialdirection R-R.

Said braking band 1 comprises two mutually facing plates 3, 4.

Said plates 3, 4 comprise inner surfaces 5, 6, either directly orindirectly mutually facing and delimiting a gap 7 which defines aventilation duct for the braking band 1.

Said plates 3, 4 comprise outer surfaces 8, 9.

Said outer surfaces 8, 9 comprise flat and mutually oppositecircumferential portions which form braking surfaces 10, 11. In otherwords, portions of the outer surfaces 8, 9 cooperate with brake padsreceived in a brake caliper to exert a braking action when sandwichedagainst the braking band 1. The portion of the outer surfaces 8, 9 whichis brushed or involved by the pads defines the braking surfaces 10, 11.

Said plates 3, 4 comprise a plate body 12, 13 having an extension inaxial direction X-X or plate thickness 14, 15. In other words, whenassessed in axial direction, each plate 3, 4 shows a plate thickness14,15 which is given by the thickness in axial direction of the platebody 12 of plate 3, 4.

Said plates 3, 4 are joined to each other by heat dissipating elementsor connecting elements 16, 17, 18 of the plates 3, 4.

Said connecting elements 16, 17, 18 are shaped as columns and/or ribswhich project from a plate towards the opposite plate in the form ofbridges which connect the plates 3, 4.

At least one of the plates 3; 4 comprises at least one shaped pin 20, 21which projects from said plate 3; 4 into said gap 7, thus reaching theopposite plate 4; 3.

Said shaped pin 20, 21 forms at least one localized narrowing of saidgap 7. In other words, travelling said gap 7, a reduction of the sectionin axial direction X-X of the width of gap 7 is detected when saidshaped pin 20, 21 is reached.

Said shaped pin 20, 21 forms at least one thickening of the plate body12; 13, thus creating a localized increase of said plate thickness 14;15. In other words, considering the thickness in axial direction X-X ofthe body of a plate, thickness 14, 15 increases at said shaped pin 20,21.

According to a general embodiment, a braking band 1 of a disc for discbrake 2 of ventilated type extends between an inner diameter D1, closeto a rotation axis X-X of the braking band 1, and an outer diameter D2,far from said rotation axis X-X, said rotation axis defining an axialdirection X-X.

Said braking band 1 defines a radial direction R-R, substantiallyorthogonal to said axial direction X-X, and a circumferential directionC-C, orthogonal both to said axial direction X-X and to said radialdirection R-R, and a tangential direction T-T, punctually orthogonal toan axial direction X-X and a radial direction R-R.

Said braking band 1 comprises two mutually facing plates 3, 4.

Said plates 3, 4 comprise inner surfaces 5, 6, either directly orindirectly facing and delimiting a gap 7.

Said plates 3, 4 comprise a plate body 12, 13 having a predeterminedextension in axial direction X-X or predetermined plate thickness 14,15.

Said plates 3, 4 are joined to each other by heat dissipating andconnecting elements 16, 17, 18, also named connecting elements.

Said connecting elements 16, 17, 18 are shaped as columns and/or ribsand/or fins which project from a plate towards the opposite plate, thusforming bridges which connect the plates 3, 4 to each other.

At least one of the plates 3, 4 comprises at least one shaped pin 20, 21which projects from said plate 3, 4 into said gap reaching the oppositeplate 4, 3, thus forming at least one localized narrowing of said gap 7and a thickening of the plate body 12, 13, thus creating a localizedincrease of said plate thickness 14, 15.

Said at least one shaped pin 20, 21 remains separated from eachconnecting element 16, 17, 18, in which the thickness of the at leastone plate 3, 4 about said at least one shaped pin 20, 21 issubstantially equal to said predetermined plate thickness 14, 15.

Said at least one shaped pin 20 advantageously extends forming at leasttwo separate shaped pin branches 31, 32.

According to one embodiment, the thickness of the at least one plate 3,4 between said at least two shaped pin branches 31, 32 is substantiallyequal to said predetermined plate thickness 14, 15.

According to one embodiment, said inner surfaces 5, 6 are flat surfaces.

According to one embodiment, said plates 3, 4, comprise outer surfaces8, 9. Said outer surfaces 8, 9 comprise flat and opposite annularportions which form braking surfaces 10, 11. The distance between saidinner surfaces 5, 6 and said braking surfaces 10, 11 defines saidpredetermined plate thickness 14, 15.

According to one embodiment, the maximum axial width or axial extensionof said gap 7 is reached between said at least one shaped pin 20, 21 andeach adjacent connecting element.

According to one embodiment, said at least one shaped pin 20 and its atleast two separate shaped pin branches 31, 32 have a symmetrical shapewith respect to a plane containing an axial direction X-X and a radialdirection R-R.

According to one embodiment, said braking band 1 has an outer band edge35 at said outer band diameter D2. Viewed on a plane comprising a radialdirection R-R and circumferential direction C-C, said at least oneshaped pin 20 and its at least two separate branches 31, 32 form abranched shaped pin 34, said branched shaped pin 34 displays a“V”-shaped section which forms a concavity facing the outer edge of thedisc.

According to one embodiment, viewed on a plane comprising a radialdirection R-R and circumferential direction C-C, said at least oneshaped pin 20 and its at least two separate branches 31, form a branchedshaped pin 34, said branched shaped pin 34 is crescent-shaped.

According to one embodiment, said at least one shaped pin comprises acentral shaped pin body 36 in the shape of a cylinder, from which saidat least two separate shaped pin branches 31, 32 project.

According to one embodiment, the extensions of said at least two shapedpin branches 31, 32 are arranged straddling at least one connectingelement 16.

According to one embodiment, said braking band 1 comprises at least onefurther shaped pin 21.

According to one embodiment, the extension of at least one of said atleast two branches 31, 32 intersects said at least one further shapedpin 21.

According to one embodiment, said braking band 1 comprises at least twofurther shaped pins 21 arranged at the sides of a connecting element 16.

According to one embodiment, the extension of said at least two branches31, 32 each intersects at least one further shaped pin 21.

According to one embodiment, seen on a plane comprising a radialdirection R-R and circumferential direction C-C, said at least onefurther shaped pin 21 is drop-shaped.

According to one embodiment, said at least one further shaped pin 21 hasa further shaped pin-tapered extension 37 tapered in radial directionR-R, preferably directed towards said rotation axis X-X.

According to one embodiment, said at least one further shaped pin 21 isa plurality of further shaped pins 21.

According to one embodiment, said at least one further shaped pin 21 isa plurality of further shaped pins 21 arranged close to an outer bandedge 35.

According to one embodiment, said at least one further shaped pin 21 isa plurality of further shaped pins 21 evenly distributed along acircumference.

According to one embodiment, said at least one further shaped pin 21 isa plurality of further shaped pins 21 arranged between a plurality ofconnecting elements 16.

According to one embodiment, said at least one shaped pin 20 and its atleast two separate shaped pin branches 31, 32 are a plurality of shapedpins 20, each with respective at least two separate shaped pin branches31, 32.

According to one embodiment, said at least one shaped pin 20 and its atleast two separate shaped pin branches 31, 32 are a plurality of shapedpins 20 evenly distributed along a circumference.

According to one embodiment, said at least one shaped pin 20 and its atleast two separate shaped pin branches 31, 32 are a plurality of shapedpins 20 arranged at least in part between connecting elements 17.

According to one embodiment, at least one circumference concentric tothe rotation axis X-X of the braking band 1, which is arranged on saidinner surfaces 5, 6 and intersects said connecting elements 17 of aninner or intermediate rank, also intersects said at least one shaped pin20.

According to one embodiment, at least one circumference concentric witha rotation axis X-X of the braking band 1, which is arranged on saidinner surfaces 5, 6 and intersects said connecting elements 16 of anouter rank, also intersects said at least one further shaped pin 21.

According to one embodiment, viewed on a plane comprising a radialdirection R-R and circumferential direction C-C, said at least oneshaped pin 20 and its at least two separate branches 31, 32 form abranched shaped pin 34, said branched shaped pin 34 has a rounded outershaped pin surface 38 connected to said inner surface 5 or 6 from whichit projects into gap 7.

According to one embodiment, viewed on a plane comprising a radialdirection R-R and circumferential direction C-C, said at least onefurther shaped pin 21 has a further shaped pin-rounded outer surface 39connected to said inner surface 5 or 6 from which it projects into gap7.

According to one embodiment, said connecting elements 16, 17, 18 aregrouped into at least two rows or ranks 23, 24, 25 arrangedcircumferentially. A first of said ranks 23 is arranged internally in aradial direction or towards said axis X-X close to said inner diameterD1. A second of said ranks 24 is radially located further from said axisX-X close to said outer diameter D2.

According to one embodiment, at least one third of said ranks 24 isarranged radially between said first inner row 23 and said second outerrow 24.

According to one embodiment, each of said connecting elements 16 of saidsecond of said rows 24 has three shaped pins or combination of shapedpins facing it on three sides, and further shaped pins 20, 21.

According to one embodiment, said at least one shaped pin 20 or 21 is atleast a plurality of shaped pins, each plurality of said shaped pins 20or 21 is arranged between connecting elements 16 or 17 of the same rank23, 24.

According to one embodiment, at least some of said connecting elements16, 17, 18 are fins or ribs which have, on a plane substantiallyparallel to the air flow along gap 7, an elongated shape section, e.g.in the radial direction R-R.

According to one embodiment, said connecting elements 16 close to theouter band diameter D2 or outer rank 24 have an elongated drop-shapedsection in radial direction R-R on a plane substantially parallel to theflow of air along gap 7.

According to one embodiment, at least two of said connecting elements17, 18 have, on a plane substantially parallel to the air flow along gap7, a diamond- or rhombus-shaped section 27 with four vertices 28 joinedby four sides 29 in which said sides delimiting said sectionsubstantially are rectilinear in shape.

According to one embodiment, all the shaped pins 20, 21 of said shapedpins 20, 21 are arranged in a circular portion of said gap 7 close tosaid outer band diameter D2.

According to one embodiment, all the shaped pins 20, 21 of said shapedpins 20, 21 are arranged in a circular portion of said gap 7 close towhere an outer rank 24 of connecting elements 16 is present.

The present invention likewise relates to a disc brake disc 2 comprisinga braking band 1 according to any one of the above-describedembodiments.

The present invention likewise relates to a vehicle comprising a brakingband 1 according to any one of the above-described embodiments.

Those skilled in the art may make several changes and adaptations to theabove-described embodiments, and may replace elements with others whichare functionally equivalent in order to meet contingent and specificneeds, without however departing from the scope of the following claims.

The assembly of shaped pins 20, 21 arranged close to one another forms agroup of shaped pins 20, 21 which is arranged circumferentially, thuscreating a circumferential distribution which has circumferentialdiscontinuities concentrated close to the outer diameter D2 of thebraking band and capable of creating an uneven distribution of theassembly of shaped pins, a distribution adapted to avoid the presence ofvibrating modes of the braking band which, when arranged to resonate,create annoying noises or whistling.

An embodiment of the present invention is described below.

According to one embodiment, a braking band 1 has an outer diameter D2of 415 mm, an inner diameter of 295 mm and a thickness of 33 mm.

Gap 7, or the ventilation channel, has a height assessed in axialdirection X-X of 12.6 mm.

The two plates 3, 4 are connected to each other by connecting elements16, 17, 18 in the form of columns arranged over three concentric rows orranks 23, 24, 25 and said connecting elements 16, 17, 18 are arrangedaccording to a staggered arrangement.

The connecting elements in the outer rank 24 have a drop shape assessedon an average flow plane which travels gap 7, with tapered extensiondirected according to the radial direction R-R and facing the rotationaxis X-X.

The connecting elements 17, 18 in the intermediate rank 25 and innerrank 23 have a rhomboidal shape assessed on an average flow plane whichtravels gap 7.

Each rank has 47 connecting elements 16 or 17 or 18.

Further shaped pins 21 are present in the outer rank 23 between eachconnecting element 16. Said further shaped pins 21 have a drop shape ona plane containing a radial direction R-R and circumferential directionC-C, with tapered extension directed according to the radial directionR-R and facing the rotation axis X-X.

Shaped pins 20 are present in the intermediate rank 25 between eachconnecting element 17. Said further shaped pins 20 have, on a planecontaining a radial direction R-R and circumferential direction C-C, abranched shape 34, i.e. a cylindrical central body from which a firstand a second shaped pin branch 31, 32 project separately from eachother.

Said shaped pin 20 has extension in axial direction of 3.4 mm. The baseof said shaped pin 20 has a radius of 4 mm. The overall height of theshape of the shaped pin 20 is 9.7 mm and the overall width including thebranches is 13.5 mm.

The outer surface 38 of the shaped pin 20 is joined to the flat innersurface 5 or 6 with a radius of 2 mm.

The modal analysis performed in a frequency range from 20 to 10,000 Hz(with material having Young's modulus of 112,000 MPa, Poisson's ratio of0.263 and a density of 7.113 kg/dm) showed the following values ofinterest compared with the solution described in EP 2 715 179 B1 of thesame Applicant;

Mode 1 Mode II Mode III K(0; 2) K(0; 3) K(0; 4) 1 projection band discfrequency 530 1271 2054 [Hz] according to EP 2 715 179 B1 2 projectionband (half-moon) disc 526 1260 2038 frequency [Hz] according to thepresent invention % further reduction −0.75% −0.87% −0.78%

LIST OF REFERENCES

-   1 braking band-   2 disc brake disc-   3 plate-   4 plate-   5 inner surface-   6 inner surface-   7 gap-   8 outer surface-   9 outer surface-   10 braking surface-   11 braking surface-   12 plate body-   13 plate body-   14 plate thickness-   15 plate thickness-   16 connecting elements-   17 connecting elements-   18 connecting elements-   20 shaped pin-   21 shaped pin-   23 ranks-   24 ranks-   25 ranks-   26 pins-   27 fins or ribs-   28 rhombus or diamond with four vertices-   29 rhombus sides-   31 first shaped pin branch-   32 second shaped pin branch-   33 bell-   34 branched shaped pin-   35 outer band edge-   36 central shaped pin body-   37 tapered extension of further shaped pin-   38 outer shaped pin surface-   39 outer surface of further shaped pin-   A-A rotation axis of the braking band or brake disc-   X-X rotation axis or axial direction-   R-R radial direction-   C-C tangential direction-   D1 inner band diameter-   D2 outer band diameter

1-10. (canceled)
 11. A braking band of a disc brake disc of ventilatedtype, said braking band extending between an inner diameter, near arotation axis (X-X) of the braking band, and an outer diameter, far fromsaid rotation axis (X-X), said rotation axis (X-X) defining an axialdirection (X-X); said braking band defining a radial direction (R-R),orthogonal to said axial direction (X-X), and a circumferentialdirection (C-C), orthogonal to said axial direction (X-X) and to saidradial direction (R-R), and a tangential direction (T-T) orthogonal tosaid axial direction (X-X) and said radial direction (R-R); said brakingband comprising two mutually facing plates; said two mutually facingplates comprising inner surfaces, either directly or indirectly facingand delimiting a gap; said two mutually facing plates each comprising aplate body having a predetermined extension in the axial direction (X-X)or a predetermined plate thickness; said two mutually facing platesbeing joined to each other by heat dissipating and connecting elements,hereinafter connecting elements; said connecting elements being shapedas columns, ribs or fins which project from one plate of said twomutually facing plates towards an opposite plate of said two mutuallyfacing plates, forming bridges which connect the two mutually facingplates to each other; wherein one plate of the two mutually facingplates comprises at least one shaped pin which projects from said plateinto said gap reaching the opposite plate of said two mutually facingplates, forming at least one localized narrowing of said gap and athickening of the plate body, creating a localized increase of saidpredetermined plate thickness; wherein said at least one shaped pinremains separated from each connecting element, wherein a thickness ofat least one plate of said two mutually facing plates about said atleast one shaped pin is substantially equal to said predetermined platethickness; and wherein said at least one shaped pin extends forming atleast two separate shaped pin branches.
 12. The braking band of claim11, wherein the thickness of at least one plate of said two mutuallyfacing plates between said at least two separate shaped pin branches issubstantially equal to said predetermined plate thickness; said twomutually facing plates comprise outer surfaces; said outer surfacescomprise flat and opposite annular portions which form braking surfaces;and a distance between said inner surfaces and said braking surfacesdefines said predetermined plate thickness; said braking band furthercomprising at least one of the following features: said inner surfacesare flat surfaces; a maximum axial width or axial extension of said gapis reached between said at least one shaped pin and each adjacentconnecting element.
 13. The braking band of claim 11, wherein said atleast one shaped pin and said at least two separate shaped pin brancheshave a symmetrical shape with respect to a plane containing the axialdirection (X-X) and the radial direction (R-R); and wherein said brakingband further comprises at least one of the following features or acombination thereof: said braking band comprises a band outer edge atsaid band outer diameter; viewed on a plane comprising the radialdirection (R-R) and the circumferential direction (C-C), said at leastone shaped pin and the at least two separate shaped pin branches form abranched shaped pin, and said branched shaped pin has a V-shaped sectionwhich forms a concavity facing the band outer edge; viewed on a planecomprising the radial direction (R-R) and the circumferential direction(C-C), said at least one shaped pin and the at least two separate shapedpin branches form a branched shaped pin, and said branched shaped pin iscrescent-shaped; said at least one shaped pin comprises acylinder-shaped central body from which said at least two separateshaped pin branches project.
 14. The braking band of claim 13, whereinextensions of said at least two separate shaped pin branches arearranged straddling at least one connecting element.
 15. The brakingband of claim 11, wherein said braking band comprises at least onefurther shaped pin; and wherein said braking band further comprises atleast one of the following features or a combination thereof: anextension of at least one of said at least two separate shaped pinbranches intersects said at least one further shaped pin; said brakingband comprises at least two further shaped pins arranged at sides of oneconnecting element; extensions of said at least two separate shaped pinbranches each intersect at least one further shaped pin; viewed on aplane comprising the radial direction (R-R) and the circumferentialdirection (C-C), said at least one further shaped pin is drop-shaped;said at least one further shaped pin comprises a further shaped pintapered extension, tapered in radial direction (R-R).
 16. The brakingband of claim 15, wherein said at least one further shaped pin is aplurality of further shaped pins; and wherein said braking band furthercomprises at least one of the following features or a combinationthereof: said at least one further shaped pin is a plurality of furthershaped pins arranged near a band outer edge; said at least one furthershaped pin is a plurality of further shaped pins evenly distributedalong a circumference; said at least one further shaped pin is aplurality of further shaped pins arranged between a plurality ofconnecting elements; said at least one shaped pin and the at least twoseparate shaped pin branches are a plurality of shaped pins, each withrespective at least two separate shaped pin branches; said at least oneshaped pin and the at least two separate shaped pin branches are aplurality of shaped pins evenly distributed along a circumference; saidat least one shaped pin and the at least two separate shaped pinbranches are a plurality of shaped pins arranged at least in partbetween the connecting elements; at least one circumference concentricto the rotation axis (X-X) of the braking band, arranged on said innersurfaces and intersecting the connecting elements of an inner orintermediate rank, also intersects said at least one shaped pin; atleast one circumference concentric to the rotation axis (X-X) of thebraking band, arranged on said inner surfaces and intersecting theconnecting elements of an outer rank, also intersects said at least onefurther shaped pin; viewed on a plane comprising the radial direction(R-R) and the circumferential direction (C-C), said at least one shapedpin and the at least two separate shaped pin branches form a branchedshaped pin, said branched shaped pin comprising a rounded shaped pinouter surface connected to an inner surface from which it projects intothe gap; viewed on a plane comprising the radial direction (R-R) and thecircumferential direction (C-C), said at least one further shaped pincomprises a further shaped pin rounded outer surface connected to aninner surface from which it projects into the gap.
 17. The braking bandof claim 11, wherein said connecting elements are grouped into at leasttwo ranks arranged circumferentially; wherein a first rank of said atleast two ranks is an inner rank internally arranged in the radialdirection or towards said rotation axis (X-X) near said inner diameter;and wherein a second rank of said at least two ranks is an outer rankradially located further from said rotation axis (X-X) near said outerdiameter; and wherein said braking band further comprises at least oneof the following features or a combination thereof: at least one thirdor intermediate rank is radially arranged between said inner rank andsaid outer rank; each connecting element of said outer rank comprisesthree shaped pins or a combination of shaped pins facing said connectingelement on three sides, and further shaped pins; said at least oneshaped pin is at least a plurality of shaped pins, and each plurality ofshaped pins is arranged between the connecting elements of a same rank.18. The braking band of claim 17, wherein at least some of saidconnecting elements are fins or ribs having, on a plane substantiallyparallel to air flow along the gap, an elongated shape section in theradial direction (R-R); and wherein said braking band further comprisesat least one of the following features or a combination thereof: theconnecting elements close to the outer diameter or outer rank have anelongated drop-shaped section in the radial direction (R-R) on a planesubstantially parallel to air flow along the gap; at least two of saidconnecting elements have, on a plane substantially parallel to air flowalong the gap, a diamond or rhombus-shaped section with four verticesjoined by four sides, said four sides being rectilinear in shape; allthe shaped pins are arranged in a circular portion of said gap near saidouter diameter; all the shaped pins are arranged in a circular portionof said gap near which the outer rank of connecting elements is present.19. A disc brake disc comprising a braking band according to claim 11.20. A vehicle comprising a braking band according to claim 11.